Indoor television receiving antenna



March 17, 1953- 1.. F. ROBERTS 2,632,105

INDOOR TELEVISION RECEIVING ANTENNA Filed June 10, 1949 2 SHEETS-SHEET 1 FIG.2

INVENTOR.

Lawrence F. Rober'rs ATTORNEY March 17, 1953 L. F. ROBERTS INDOOR TELEVISION RECEIVING ANTENNA Filed June 10, 1949 2 SHEETSSHEET 2 Fl G. 5 5o 80 FIG. 7

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m Y if A 77 76 75 I 8 75 6'54| 74 74 64 as 3 Lee 61 57 55 73 13 72 7O fol INVENTOR. Lowrenc F. Roberts Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE INDOOR TELEVISION RECEIVING ANTENNA Lawrence F. Roberts, New York, N. Y. Application June 10, 1949, Serial No. 98,192

3 Claims. (Cl. 250-43) My object is to provide a simple, compact, effective and portable receiving antenna suitable for use indoors.

Another object is to improve the tuning of the antenna. To carry out these objects, I provide a portable instrument having receiving branches carried by a switch panel by which the circuit may be instantly tuned to the desired frequency by. adjustment of the switch of a suitable type.

I have accordingly designed the receiver as a sort of grid to which switch contacts are connected at points corresponding to the frequency of standard television channels now existing. It should be understood however that the invention is equally applicable to other recognized frequencies.

Fig. l is a perspective view on a small scale showing one form of television receiving antenna involving my invention.

Fig. 2 is a front view on a larger scale showing the switch panel and parts of the antenna branches and someof the switch elements of a rotary type switch diagrammatically.

Fig. 3 is an enlarged fragmentary sectional view taken on the plane of the line 3-3 of Fig. 2.

Fig. 4 is a front view showing the panel for a sliding type switch. I

Fig. 5 is a vertical sectional view of the switch of the type of Fig. 4.

Fig. 6 is a vertical sectional view and edge view showing the switch elements of Figs. 4 and 5.

Fig. '7 is a fragmentary plan and sectional view showing elements of the switch of Figs. 4 and 5.

The antenna has two branches I0 and II carried by a support l2 which is mounted to be rotated on a base I3. The antenna is connected to a television receiving set l4 by a two-wire lead-in conductor l5. The support is formed of insulating material and encloses a switch l6 of a rotary, sliding or plug-in-type to which the conductor lead is connected.

Fig. 2 shows a conventional rotary di-pole switch with contacts to permit adjustment to approved channels. The antenna for the maximum wave length reception consists of the receiving elements ll, l8, l9 and 20 with the connections 2!, 22 and 23, a total length for the two branches of approximately 97 for tuning to channel #2. The outer end of element 20 is connected by an insulated wire 24 extending from the clip 25 to a contact 26 of the switch Hi.

The switch has an opposite contact 26 connected to the extension wire 24' of the element 2 20. These conductors 24 and 24,' are,laid parallel with the elements 20, 20, respectively. In fact it is preferred that the elements l1, I8, 19 and 20 all be tubular so that the conductors such as 24 may be enclosed within them when shunting wires are required.

In the form of switch of Fig. 2, there are two switch contact segments 21, 2'! having tabs 28 to which the ends of the conductor 15 are connected. The switch is of the rotary type having bridging contacts 29 which connect thesegmental contacts 21, 21' with the antenna terminal contacts 26, 26' etc. v

The contacts 30, 30' are connected by insulated wires 3|, 3| with the inner ends of the elements l1, ll, respectively, which are each approximately 13" long for tuning in channel #13.

Contact 32 is connected by an insulated wire 33 to a clip 34 on element [8 and contact 32' to a clip at a corresponding point on element I8 to provide for a wave length of approximately 29.3" for tuning in channel #9.

Similarly contact 35 is connected by an insulated wire 36 to clip 3'! on element l8 of the left hand branch [0 to provide for reception of a wave length of 31.2" for tuning in channel #7.

Contact 38 is connected by an insulated wire 39 to the inner, end of element 19 to provide for the reception of a wave length on channel #5.

Contact 40 is connected by an insulated wire 4| to a clip 42 on element 20 of the left hand branch for reception of an wave length on channel #4.

Contacts 35, 38 and 40 of course have their counterparts for connection to the elements of the right hand branch II.

The wave lengths for channels #11 and #13 are so close together that wire 43 may be connected to the same contact 30 as wire 3!.

In the form of switch shown in Figs. 4 and 5, the switch panel 50 is rotatably supported on the base 5] and carries the branch receiving elements 52, 53, 54 and 55 similar to the elements l1, l8. I9, 20 of Figs. 1 and 2 and the connectors 56 and 51 corresponding to connectors 2| and 23 and the elements 52', 53, 54' and 55 will be opposite 52, 53, 54 and 55.

In this form the switch is of the sliding type having an insulating cross bar 58 carried by a shaft 59 having a knob 60. This shaft 59 slides up and down in a slot 6| in the face plate of the panel 50 and is frictionally held by two washers 62, 63 and springs 64 and 65. On the opposite ends of bar 58 are mounted spring contacts 66 3 and 61 to which the conductors 68 and 69 of the television receiving set are connected.

The stationary switch contacts 70, 70' are connected to the outer ends of the elements 55 and 55' by wires H, H such as shown at 12 in Fig. so that when the slide is down at the bottom of the slot 6i the full length of the branches of the antenna will be connected in circuit with the television set tuned to channel 2.

By raising the slide until the contacts 66 and 61 engage the ends 73, 73 the lower elements 55 and 55 will be connected in circuit and the set tuned to channel #4..

When the cross bar 58 is moved so that the contacts 66 and 6! engage the ends 14, 74' of elements 54 and 54 the antenna will be tuned to channel #5. Y

Terminal 75 is connected by wire to the clip 77 on element 53 and terminal 75 similarly connected by wire 75 to a clip on element 53 to provide for tuning into channel #7.

Terminals 18 and 78' when bridged by the contacts 66 and 67 tune the antenna to channel #11.

Terminals 80, 80 provide for further slight adjustment of the tuning to channel #13.

Although I have shown a sliding adjustment for tuning the antenna it should be understood that the bridging contacts might be constructed from plug-in connection to the respective stationary contacts.

It will be understood that the television receiving set per se will be tuned for reception of the desired frequency and that the antenna system will be oriented to the proper sending station by simply rotating the support with the receiving arms.

I claim:

1. A television receiving antenna comprising a rotatable support, a number of parallel tubular receiving elements projecting from opposite sides or the support and some of which are connected in series to form branches for receiving signals of maximum wave lengths, switching means for connecting said branches to a television receiving set, said means including a switch having at least one movable arm and a plurality of contacts engageable thereby, and conductors extending from certain of said contacts to intermediate points of the respective branches correspondent to shorter wave lengths, and positioned with said tubular elements.

2. A television receiving antenna system comprising a supporting switch panel, a number of wave receiving elements arranged in branches extending oppositely from said panel, each branch entering said panel and being supported thereby, the elements of each branch being connected in series to receive signals of maximum Wave length, switch contacts connected to the inner ends of said connected elements and other switch contacts carried by said panel connected to intermediate points of said elements corresponding with other shorter wave lengths, said contacts being arranged to make connection with the input end of a television receiving set.

3. In an indoor television receiving antenna system, a panel support having a plurality of pairs of opposed switch contacts, main wave receiving elements of lengths representing the maximum receiving wave length available carried by said support and connected at their inner ends to one pair of said contacts and extending oppositely therefrom, and insulated conductors connected at their inner ends to the contacts of other pairs of said contacts and extending parallel with the main elements and connected to said receiving elements at points therealong representing shorter wave lengths and a conductor pair for a receiving set having terminal means for connecting the pair to the contacts.

LAWRENCE F. ROBERTS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,424,365 Loftin et al Aug. 1, 1922 1,554,328 Brenner Sept. 22, 1925 1,615,755 Graue Jan. 25, 1927 1,892,958 Leib Jan. 3, 1933 2,188,649 Carter Jan. 30, 1940 2,272,608 Hoffman Feb. 10, 1942 2,328,024 Limb Aug. 31, 1943 2,403,093 Lear July 2, 1946 

